In last month's cyberattack, the malicious computer codes and the technique employed were similar to those used in prior attacks traced back to North Korea, the officials noted.

The attack, which marked the 63rd anniversary of the beginning of the Korean War, targeted multiple government and private Web sites. At the time, a South Korean spokesman said that the attack mimicked past attempts by North Korea to hack into key Web sites. The spokesman pointed the finger at an espionage agency run by the North Korean military.

North Korea has consistently denied involvement in any cyberattacks launched against the South.